Possible Clues:

• People using private transport could be a bloomer
• Pink people who don't like to walk?
• With private transport, people will be in the pink!
• Not in a car (anag) - plant
• Something blooming like the Americans
• The flower of a mechanical people
• Those blooming Americans and their automobiles?
• The sort of blooming people that the human race is becoming
• Buttonhole character endlessly on race?
• Pink vehicle pursued by News at Ten getting clamped